HS-cellulose sulfate catalyzed synthesis of dihydroquinazolinones derivatives in water.

Entrya	R1	R2	Pro	Time (h)	Yieldb (%)
1	–C6H5	H	3a	0.7	94 (90, 88, 82)c
2	4-CH3–C6H4	H	3b	1.5	87
3d	4-N(CH3)2–C6H4	H	3c	1.5	98
4	4-OCH3–C6H4	H	3d	1.0	86
5	4-NO2–C6H4	H	3e	1.0	87
6	4-COOH–C6H4	H	3f	2.0	91
7d	4-C6H5–C6H4	H	3g	2.0	80
8	4-F–C6H4	H	3h	1.0	89
9d	4-Br–C6H4	H	3i	1.5	85
10d	4-Cl–C6H4	H	3j	1.5	92
11	2-Cl–C6H4	H	3k	2.0	98
12	3-Cl–C6H4	H	3l	2.0	83
13	4-OH–3-OCH3–C6H4	H	3m	1.0	95
14	–C4H3S	H	3n	2.0	88
15	–C6H5	4-NO2	3o	1.5	91
16	4-CH3–C6H5	4-NO2	3p	1.5	90
17	4-Cl–C6H5	4-NO2	3q	1.5	89
18	2-Cl–C6H5	4-NO2	3r	2.0	92
19	–C6H5	5-Cl	3s	6.0	N.R
20	–C6H5	5-OCH3	3t	6.0	Trace

^aReaction conditions: aromatic aldehyde (0.5 mmol), aminobenzamide (0.5 mmol), HS-cellulose sulphate (10 mg), 60 °C; water (1.5 mL). The reactions were run until completion as indicated by TLC. N.R: no reaction. All the compounds are known, characterized by ¹H NMR and ¹³C NMR.

^bIsolated yield.

^cThe recovered catalyst cycle yield.

^dThe solvent was water : ethanol = 1 : 1.